Tuberculosis exposure, infection and disease in children: a systematic diagnostic approach

Current approaches for diagnosis of subclinical pulmonary tuberculosis, clinical implications and future perspectives: a scoping review

INTRODUCTION

Subclinical tuberculosis (TB) is the presence of TB disease among people who are either asymptomatic or have minimal symptoms.

AREAS COVERED

Currently, there are no accurate diagnostic tools and clear treatment approaches for subclinical TB. In this study, a comprehensive literature search was conducted across major databases. This review aimed to uncover the latest advancements in diagnostic approaches, explore their clinical implications, and outline potential future perspectives. While innovative technologies are in development to enable sputum-free TB tests, there remains a critical need for precise diagnostic tools tailored to the unique characteristics of subclinical TB. Given the complexity of subclinical TB, a multidisciplinary approach involving clinicians, microbiologists, epidemiologists, and public health experts is essential. Further research is needed to establish standardized diagnostic criteria and treatment guidelines specifically tailored for subclinical TB, acknowledging the unique challenges posed by this elusive stage of the disease.

EXPERT OPINION

Efforts are needed for the detection, diagnosis, and treatment of subclinical TB. In this review, we describe the importance of subclinical TB, both from a clinical and public health perspective and highlight the diagnostic and treatment gaps of this stage.

Knowledge, attitudes, and practices towards childhood tuberculosis among healthcare workers at two primary health facilities in Lusaka, Zambia

BACKGROUND

Zambia is among the 30 high-burden countries for tuberculosis (TB), Human Immunodeficiency Virus (HIV)-associated TB, and multi-drug resistant/rifampicin resistant TB with over 5000 children developing TB every year. However, at least 32% of the estimated children remain undiagnosed. We assessed healthcare workers' (HCWs) knowledge, attitudes, and practices (KAP) towards childhood TB and the factors associated with good KAP towards childhood TB.

METHODS

Data was collected at two primary healthcare facilities in Lusaka, Zambia from July to August 2020. Structured questionnaires were administered to HCWs that were selected through stratified random sampling. Descriptive analysis was done to determine KAP. A maximum knowledge, attitude, and practice scores for a participant were 44, 10, and 8 points respectively. The categorization as either "poor" or "good" KAP was determined based on the mean/ median. Logistic regression analysis was performed to assess the associations between participant characteristics and KAP at statistically significant level of 0.05%.

RESULTS

Among the 237 respondents, majority were under 30 years old (63.7%) and were female (72.6%). Half of the participants (50.6%) were from the outpatient department (OPD) and antiretroviral therapy (ART) clinic, 109 (46.0) had been working at the facility for less than 1 year, 134 (56.5%) reported no previous training in TB. The median/mean KAP scores were 28 (IQR 24.0-31.0), 7 (IQR = 6.0-8.0) and 5 points (SD = 1.9) respectively. Of the participants, 43.5% (103/237) had good knowledge, 48.1% (114/237) had a good attitude, and 54.4% (129/237) had good practice scores on childhood TB. In the multivariate analysis, clinical officers and individuals with 1-5 years' work experience at the facility had higher odds, 2.61 (95% CI = 1.18-5.80, p = 0.018) and 3.09 (95% CI = 1.69-5.65, p = 0.001) of having good attitude respectively, and medical doctors had 0.17 lower odds (95% CI = 0.18-5.80, p = 0.018) of good childhood TB practice. Other participant characteristics didn't show a significant association with the scores.

CONCLUSION

The study found suboptimal levels of knowledge, attitude, and practices regarding childhood TB among HCWs. Targeted programmatic support needs to be provided to address the above gaps.

Raised circulatory T regulatory cells in paediatric tuberculosis - An environment for bacterial persistence?

OBJECTIVES

T-regulatory cells (Tregs) restrain the Th1-mediated immune response and thus may help in persistence and dissemination of childhood Tuberculosis. This study compared the percentage of Tregs in peripheral blood of paediatric TB patients (severe and non severe) with healthy individuals by flow cytometry.

METHODS

Study enrolled 40 subjects, less than 12 years along with 20 age matched healthy controls. Cases were further classified as severe TB and non severe TB. Haematological work-up and flow-cytometry for Tregs was done. Tregs were quantified as CD4CD25 high and CD4FoxP3 cells and compared in different groups using the Mann-Whitney U test.

RESULTS

In cases, CD4CD25 high Tregs (%) ranged from 0.55 to 12.8 with a Mean ± SD of 3.61 ± 2.98 and CD4FoxP3 Tregs (%) ranged from 0.02 to 13.44 with a Mean ± SD of 3.56 ± 2.76. In controls, CD4CD25 high Tregs (%) ranged from 0.3 to 6.5 with a Mean ± SD of 1.29 ± 1.4 and CD4FoxP3 Tregs (%) ranged from 0.33 to 2.59 with a Mean ± SD of 1.57 ± 0.58. Thus the percentage of both CD4CD25 high and CD4FoxP3 Tregs were significantly higher in cases as compared to controls (p value, 0.001 and 0.001 respectively), however the difference was not significant between severe versus non-severe TB (p value, 0.827 and 0.880 respectively).

CONCLUSION

Children with TB (both pulmonary and extra-pulmonary) demonstrate increased number of T regulatory cells as compared to healthy controls. However, the number of Tregs are not significantly different between cases with severe versus non severe TB.

Critical Review of Tuberculosis Diagnosis in Children from Papua New Guinea Presenting to Health Facilities in the Torres Strait Islands, Australia

Paediatric tuberculosis can be challenging to diagnose, and various approaches are used in different settings. A retrospective review was conducted on Papua New Guinea (PNG) children with presumptive TB who presented for health care in the Torres Strait Islands, Australia, between 2016 and 2019. We compared diagnostic algorithms including the modified Keith Edwards TB Score, The Union Desk Guide, and the new World Health Organization (WHO) algorithm, with diagnostic practices used in the remote Torres Strait Islands. Of the 66 children with presumptive TB, 7 had bacteriologically confirmed TB. The majority (52%) were under 5 years (median age 61 months), and 45% were malnourished. There was moderate agreement across the diagnostic methods (K = 0.34; 95% CI 0.23-0.46), with the highest concordance observed between The Union Desk Guide and the WHO's algorithm (K = 0.61). Local TB physicians might have over-diagnosed presumed lymph node TB while under-diagnosing TB overall. Enhancing the precision and promptness of paediatric TB diagnosis using practical tools is pivotal to decrease TB-related child mortality, notably in isolated regions like the Torres Strait and the Western Province of PNG.

Pediatric multi-drug-resistant tuberculosis in Germany - diagnostic and therapeutic challenges of an "orphan disease"

Delay in diagnosing multidrug-resistant tuberculosis (MDR-pTB) in children prolongs time to effective treatment. Data on risk factors for pediatric MDR from low-incidence countries are scarce. Retrospective nationwide case-control study to analyze MDR-pTB cases in Germany between 2010 and 2020 in comparison to a drug-susceptible (DS)-pTB group. We included 52 MDR cases (24 tuberculosis (TB), 28 TB infection (TBI); mean age 7.3 years) and 56 DS cases (31 TB, 26 TBI; mean age 7.9 years). Groups were similar for sex, household size, and migration background. Compared to the DS group, more children with MDR were born in the Commonwealth of Independent States (CIS) (22% MDR-pTB vs. 13% DS-pTB, n.s.) and had more MDR index cases (94% MDR-pTB, 5% DS-pTB, p < 0.001). The interval between first healthcare contact and initiation of effective therapy was significantly longer in MDR-pTB (47 days) than in DS-pTB (11 days, p < 0.001), correlating with disease progression. Treatment for MDR-pTB was successful in 74%, but 22% experienced long-term adverse effects (e.g., hepatopathy, hearing loss).

CONCLUSIONS

Close contact to MDR cases or birth in MDR-TB-high-incidence countries are risk factors for MDR-pTB. Early identification of potential MDR index cases by contact investigation, and susceptibility testing in children from high-burden MDR-TB countries are essential for timely diagnosis and treatment, reducing the severity of disease and treatment side effects.

TRIAL REGISTRATION

Deutsches Register Klinischer Studien ( https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00023817 ), DRKS00023817, 2020-09-08.

WHAT IS KNOWN

•Management of children with MDR-TB remains challenging due to difficulties in diagnosing MDR-TB (lack of information on MDR index case, lack of microbiological confirmation in paucibacillary disease). •Choice of treatment regimen and monitoring of side effects.

WHAT IS NEW

•Children with an MDR-TB index or born in a MDR-TB-high-incidence country are at higher risk of developing MDR-TB in a low incidence country. •The time lag to initiate treatment in MDR-TB is longer than in DS-TB and MDR-TB treatment involves a higher risk of adverse effects in longer treatment regimens especially with injectables.

Challenges of Diagnosing Mendelian Susceptibility to Mycobacterial Diseases in South Africa

Inborn errors of immunity (IEI) are genetic disorders with extensive clinical presentations. They can range from increased susceptibility to infections to significant immune dysregulation that results in immune impairment. While IEI cases are individually rare, they collectively represent a significant burden of disease, especially in developing countries such as South Africa, where infectious diseases like tuberculosis (TB) are endemic. This is particularly alarming considering that certain high penetrance mutations that cause IEI, such as Mendelian Susceptibility to Mycobacterial Disease (MSMD), put individuals at higher risk for developing TB and other mycobacterial diseases. MSMD patients in South Africa often present with different clinical phenotypes than those from the developed world, therefore complicating the identification of disease-associated variants in this setting with a high burden of infectious diseases. The lack of available data, limited resources, as well as variability in clinical phenotype are the reasons many MSMD cases remain undetected or misdiagnosed. This article highlights the challenges in diagnosing MSMD in South Africa and proposes the use of transcriptomic analysis as a means of potentially identifying dysregulated pathways in affected African populations.

Strategies to increase childhood tuberculosis case detection at the primary health care level: Lessons from an active case finding study in Zambia

INTRODUCTION

In high TB burden settings, it is estimated that 10-20% of total notifications should be children, however, currently only 6-8% of the total TB notifications in Zambia are children. We assessed whether the implementation of a multicomponent strategy, at primary healthcare facilities, that systematically targets barriers at each step of the childhood TB diagnostic cascade can increase childhood TB case detection.

METHODS

We conducted a controlled, interrupted time series analysis to compare childhood TB case notifications before (January 2018-December 2019), and during implementation (January 2020-September 2021) in two intervention and two control Level 1 hospitals in Lusaka, Zambia. At each of the intervention facilities, we implemented a multicomponent strategy constituting: (1) capacity development on childhood TB and interpretation of chest x-ray, (2) TB awareness-raising and demand creation activities, (3) setting up fast track TB services, (4) strengthening of household contact tracing, and (5) improving access to digital chest X-ray for TB screening and Xpert MTB/Rif Ultra for TB diagnosis, through strengthening sample collection in children.

FINDINGS

Among 5,150 children < 15 years screened at the two intervention facilities during the study period, 503 (9.8% yield) were diagnosed with TB. Of these, 433 (86.1%) were identified through facility-based activities (10.5% yield) and 70 (13.9%) were identified through household contact tracing (6.9% yield). Overall, 446 children (88.7%) children with TB were clinically diagnosed. Following implementation of the multicomponent strategy, the proportion children contributed to total TB notifications immediately changed by +1.5% (95%CI: -3.5, 6.6) and -4.4% (95%CI: -7.5, 1.4) at the intervention and control sites, respectively (difference 6.0% [95%CI: -0.7, 12.7]), p = 0.08); the proportion of childhood notifications increased 0.9% (95%CI: -0.7, 2.5%) each quarter at the intervention sites relative to pre-implementation trends, while declining 1.2% (-95%CI: -1.8, -0.6) at the control sites (difference 2.1% [95%CI: 0.1, 4.2] per quarter between, p = 0.046); this translated into 352 additional and 85 fewer childhood TB notifications at the intervention and control sites, respectively, compared to the pre-implementation period.

CONCLUSION

A standardized package of strategies to improve childhood TB detection at primary healthcare facilities was feasible to implement and was associated with a sustained improvement in childhood TB notifications.

Pulmonary Tuberculosis in Children: A Forgotten Disease?

Even today, tuberculosis in childhood is a disease that is often undiagnosed and undertreated. In the absence of therapy with antituberculosis drugs, children in the first years of life have a high degree of severe forms and mortality. In these children, symptoms are often not very specific and can easily be confused with other diseases of bacterial, viral or fungal etiology, making diagnosis more difficult. Nevertheless, the introduction of new diagnostic techniques has allowed a more rapid identification of the infection. Indeed, Interferon gamma release assay (IGRA) is preferred to the Mantoux, albeit with obvious limitations in children aged <2 years. While the Xpert Mtb/RIF Ultra test is recommended as an initial diagnostic investigation of the gastric aspirate and/or stools in children with signs and symptoms of pulmonary tuberculosis. The drugs used in the treatment of susceptible and resistant TB are the same as those used in adults but doses and combinations are different in the pediatric age. In children, brief therapy is preferable in both the latent infection and the active disease, as a significant reduction in side effects is obtained.

UMOYA: a prospective longitudinal cohort study to evaluate novel diagnostic tools and to assess long-term impact on lung health in South African children with presumptive pulmonary TB-a study protocol

BACKGROUND

Despite a high paediatric tuberculosis (TB) burden globally, sensitive and specific diagnostic tools are lacking. In addition, no data exist on the impact of pulmonary TB on long-term child lung health in low- and middle-income countries. The prospective observational UMOYA study aims (1) to build a state-of-the-art clinical, radiological, and biological repository of well-characterised children with presumptive pulmonary TB as a platform for future studies to explore new emerging diagnostic tools and biomarkers for early diagnosis and treatment response; and (2) to investigate the short and long-term impact of pulmonary TB on lung health and quality of life in children.

METHODS

We will recruit up to 600 children (0-13 years) with presumptive pulmonary TB and 100 healthy controls. Recruitment started in November 2017 and is expected to continue until May 2023. Sputum and non-sputum-based samples are collected at enrolment and during follow-up in TB cases and symptomatic controls. TB treatment is started by routine care services. Intensive follow-up for 6 months will allow for TB cases to retrospectively be classified according to international consensus clinical case definitions for TB. Long-term follow-up, including imaging, comprehensive assessment of lung function and quality of life questionnaires, are done yearly up to 4 years after recruitment.

DISCUSSION

The UMOYA study will provide a unique platform to evaluate new emerging diagnostic tools and biomarkers for early diagnosis and treatment response and to investigate long-term outcomes of pulmonary TB and other respiratory events on lung health in children.

Trends in pediatric tuberculosis diagnosis utilizing xpert Mycobacterium tuberculosis/Rifampicin in a poor-resource, high-burden region: A retrospective, multicenter study

Background

The burden of tuberculosis (TB) in Nigeria remains high, and diagnosis in children, a challenge. We aimed to document yield from Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) as a mode of diagnosis for children and the variables associated with a positive result.

Methods

This was a retrospective review of TB treatment cards of children aged 0-15 years managed from January 2017 to December 2021 across six public tertiary institutions in Nigeria. The data obtained were analyzed using the descriptive and inferential statistics. Statistical significance was set at P < 0.05.

Results

Of 1489 children commenced on TB treatment, 1463 (97.9%) had sufficient data for analysis the median age of study participants was 60 months (interquartile range [IQR]: 24, 120), and 814 (55.6%) were males. Xpert MTB/RIF test was performed in 862 (59%) participants and MTB was detected in 171 (19.8%) participants, of which 6.4% (11/171) had RIF resistance reported. The use of Xpert MTB/RIF rose from 56.5% in 2017 to 64% in 2020 but fell to 60.9% in 2021. We found that older age (> 10 years), the presence of pulmonary TB (PTB), and a negative human immunodeficiency virus (HIV) status were associated with positive Xpert MTB/RIF tests (P = 0.002, 0.001, and 0.012, respectively).

Conclusion

The utilization of Xpert MTB/RIF in children increased in the years before the COVID-19 pandemic. Factors associated with MTB detection by Xpert MTB/RIF include older age, the presence of PTB, and a negative HIV status. Clinical and radiological evaluation continues to play vital roles in the diagnosis of childhood TB in Nigeria.

Systematic review with network meta-analysis on the treatments for latent tuberculosis infection in children and adolescents

BACKGROUND

We aimed to synthesize the evidence on the efficacy and safety of different treatment regimens for latent tuberculosis infection (LTBI) in children and adolescents.

METHODS

A systematic review with network meta-analysis was performed (CRD142933). Searches were conducted in Pubmed and Scopus (Nov-2021). Randomized controlled trials comparing treatments for LTBI (patients up to 15 years), and reporting data on the incidence of the disease, death or adverse events were included. Networks using the Bayesian framework were built for each outcome of interest. Results were reported as odds ratio (OR) with 95% credibility intervals (CrI). Rank probabilities were calculated via the surface under the cumulative ranking analysis (SUCRA) (Addis-v.1.16.8). GRADE approach was used to rate evidence's certainty.

RESULTS

Seven trials (n = 8696 patients) were included. Placebo was significantly associated with a higher incidence of tuberculosis compared to all active therapies. Combinations of isoniazid (15-25 mg/kg/week) plus rifapentine (300-900 mg/week), followed by isoniazid plus rifampicin (10 mg/kg/day) were ranked as best approaches with lower probabilities of disease incidence (10% and 19.5%, respectively in SUCRA) and death (20%). Higher doses of isoniazid monotherapy were significantly associated to more deaths (OR 18.28, 95% ICr [1.02, 48.60] of 4-6 mg/kg/day vs. 10 mg/kg/3x per week).

CONCLUSIONS

Combined therapies of isoniazid plus rifapentine or rifampicin for short-term periods should be used as the first-line approach for treating LTBI in children and adolescents. The use of long-term isoniazid as monotherapy and at higher doses should be avoided for this population.

Development of a Clinical Prediction Score Including Monocyte-to-Lymphocyte Ratio to Inform Tuberculosis Treatment Among Children With HIV: A Multicountry Study

Background

Clinical pediatric tuberculosis (TB) diagnosis may lead to overdiagnosis particularly among children with human immunodeficiency virus (CHIV). We assessed the performance of monocyte-lymphocyte ratio (MLR) as a diagnostic biomarker and constructed a clinical prediction score to improve specificity of TB diagnosis in CHIV with limited access to microbiologic testing.

Methods

We pooled data from cohorts of children aged ≤13 years from Vietnam, Cameroon, and South Africa to validate the use of MLR ≥0.378, previously found as a TB diagnostic marker among CHIV. Using multivariable logistic regression, we created an internally validated prediction score for diagnosis of TB disease in CHIV.

Results

The combined cohort had 601 children (median age, 1.9 [interquartile range, 0.9-5.3] years); 300 (50%) children were male, and 283 (47%) had HIV. Elevated MLR ≥0.378 had sensitivity of 36% (95% confidence interval [CI], 23%-51%) and specificity of 79% (95% CI, 71%-86%) among CHIV in the validation cohort. A model using MLR ≥0.28, age ≥4 years, tuberculin skin testing ≥5 mm, TB contact history, fever >2 weeks, and chest radiograph suggestive of TB predicted active TB disease in CHIV with an area under the receiver operating characteristic curve of 0.85. A prediction score of ≥5 points had a sensitivity of 94% and specificity of 48% to identify confirmed TB, and a sensitivity of 82% and specificity of 48% to identify confirmed and unconfirmed TB groups combined.

Conclusions

Our score has comparable sensitivity and specificity to algorithms including microbiological testing and should enable clinicians to rapidly initiate TB treatment among CHIV when microbiological testing is unavailable.

The Contribution of Chest Radiography to the Clinical Management of Children Exposed to Tuberculosis

Rationale: Although World Health Organization guidelines emphasize contact investigation for tuberculosis (TB)-exposed children, data that support chest radiography as a useful tool are lacking. Objectives: We evaluated the diagnostic and prognostic information of chest radiography in children exposed to TB and measured the efficacy of isoniazid preventive therapy (IPT) in those with relevant radiographic abnormalities. Methods: Between September 2009 and August 2012, we enrolled 4,468 TB-exposed children who were screened by tuberculin skin testing, symptom assessment, and chest radiography. Those negative for TB disease were followed for 1 year for the occurrence of new TB diagnoses. We assessed the protective efficacy of IPT in children with and without abnormal chest radiographs. Measurements and Main Results: Compared with asymptomatic children with normal chest films, asymptomatic children with abnormal radiographs were 25.1-fold more likely to have coprevalent TB (95% confidence interval [CI], 1.02-613.76) and 26.7-fold more likely to be diagnosed with incident TB disease during follow-up (95% CI, 10.44-68.30). Among the 29 symptom-negative and CXR-abnormal child contacts, 20% (3/15) of the isoniazid recipients developed incident TB, compared with 57% (8/14) of those who did not receive IPT (82% IPT efficacy). Conclusions: Our results strongly support the use of chest radiography as a routine screening tool for the evaluation of child TB contacts, which is readily available. Radiographic abnormalities not usually considered suggestive of TB may indicate incipient or subclinical disease, although TB preventive treatment is adequate in most cases.

Review of Pediatric Tuberculosis in the Aftermath of COVID-19

In 2014, the World Health Organization developed the End Tuberculosis Strategy with the goal of a 95% reduction in deaths from tuberculosis (TB) by 2035. The start of the COVID-19 pandemic and global lockdown has had a major impact on TB awareness, screening, diagnosis, and prompt initiation of treatment, inevitably leading to a significant setback. We explore pediatric tuberculosis through the lens of the COVID-19 era, investigating how COVID-19 has impacted pediatric TB cases in different regions of the world and what the implications are for management moving forward to mitigate these effects. Furthermore, in light of recent findings showing how exposed infants and children are at higher risk than we thought of contracting the disease, greater attention and resources are needed to prevent further downward trends.

Xpert MTB/RIF Assay for the Diagnosis of Lymph Node Tuberculosis in Children: A Systematic Review and Meta-Analysis

Background: Lymph node tuberculosis (LNTB) is the leading type of extrapulmonary tuberculosis (EPTB) causing death in children. The Xpert MTB/RIF assay is a novel rapid test for the diagnosis of LNTB. Although previous evidence suggests that Xpert is reliably accurate in diagnosing EPTB in children, information is lacking for the specific type of LNTB in children. The aim of this study was to systematically assess the accuracy and reliability of Xpert for the diagnosis of LNTB in children. Methods: We systematically searched four databases, Embase, Cochrane Library, PubMed, and Web of Science, which extracted relevant data according to predefined inclusion and exclusion criteria. The data were analyzed by meta-Disc 1.4 and Stata 12.0 software to determine sensitivity, specificity, diagnostic odds ratio (DOR), etc. Results: A total of 646 samples from 8 studies were included in the analysis. The pooled sensitivity, specificity, negative likelihood ratio (NLR), positive likelihood ratio (PLR,) and combined diagnostic odds ratio (DOR) of Xpert for all samples were 0.79 (95% CI 0.70, 0.87), 0.90 (95% CI 0.86, 0.92), 0.29 (95% CI 0.19, 0.43), 7.20 (95% CI 3.32, 15.60), and 37.56 (95% CI 13.04, 108.15), respectively. The area under the curve (AUC) of the summary receiver operating characteristic (sROC) curve was 0.9050. Conclusion: Overall, Xpert showed moderate sensitivity and high specificity compared with culture in the diagnosis of LNTB in children. In addition, after analyzing the combined diagnostic odds ratio and positive LR, our study showed that Xpert has excellent diagnostic accuracy.

Pediatric Tuberculosis Management: A Global Challenge or Breakthrough?

Managing pediatric tuberculosis (TB) remains a public health problem requiring urgent and long-lasting solutions as TB is one of the top ten causes of ill health and death in children as well as adolescents universally. Minors are particularly susceptible to this severe illness that can be fatal post-infection or even serve as reservoirs for future disease outbreaks. However, pediatric TB is the least prioritized in most health programs and optimal infection/disease control has been quite neglected for this specialized patient category, as most scientific and clinical research efforts focus on developing novel management strategies for adults. Moreover, the ongoing coronavirus pandemic has meaningfully hindered the gains and progress achieved with TB prophylaxis, therapy, diagnosis, and global eradication goals for all affected persons of varying age bands. Thus, the opening of novel research activities and opportunities that can provide more insight and create new knowledge specifically geared towards managing TB disease in this specialized group will significantly improve their well-being and longevity.

Alert sign and symptoms for the early diagnosis of pulmonary tuberculosis: analysis of patients followed by a tertiary pediatric hospital

Background

Intercepting earlier suspected TB (Tuberculosis) cases clinically is necessary to reduce TB incidence, so we described signs and symptoms of retrospective cases of pulmonary TB and tried to evaluate which could be early warning signs.

Methods

We conducted a retrospective descriptive study of pulmonary TB cases in children in years 2005–2017; in years 2018–2020 we conducted a cohort prospective study enrolling patients < 18 years accessed to Emergency Department (ED) with signs/symptoms suggestive of pulmonary TB.

Results

In the retrospective analysis, 226 patients with pulmonary TB were studied. The most frequently described items were contact history (53.5%) and having parents from countries at risk (60.2%). Cough was referred in 49.5% of patients at onset, fever in 46%; these symptoms were persistent (lasting ≥ 10 days) in about 20%. Lymphadenopathy is described in 15.9%. The prospective study enrolled 85 patients of whom 14 (16.5%) were confirmed to be TB patients and 71 (83.5%) were non-TB cases. Lymphadenopathy and contact history were the most correlated variables. Fever and cough lasting ≥ 10 days were less frequently described in TB cases compared to non-TB patients (p < 0.05).

Conclusions

In low TB endemic countries, pulmonary TB at onset is characterized by different symptoms, i.e. persistent fever and cough are less described, while more relevant are contact history and lymphadenopathy. It was not possible to create a score because signs/symptoms usually suggestive of pulmonary TB (considered in the questionnaire) were not significant risk factors in our reality, a low TB country.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-022-01288-5.

Reproducibility of a protocol for standardized reading of chest X-rays of children household contact of patients with tuberculosis

BACKGROUND

The interpretation of the chest radiograph may vary because it depends on the reader and due to the non-specificity of findings in tuberculosis (TB). We aim to assess the reproducibility of a standardized chest radiograph reading protocol in contacts of patients with pulmonary TB under the 5 years of age.

METHODS

Descriptive, cross-sectional study with children under the age of five, household contacts of patients with confirmed pulmonary TB from Medellín, Bello and Itagüí (Colombia) between Jan-01-2015 and May-31-2016. Standardized reading protocol: two radiologists, blinded independent reading, use of template (Dr. Andronikou design) in case of disagreement a third reading was performed. Kappa coefficient for intra and inter observer agreement, and prevalence ratio were estimated of sociodemographic characteristics, TB exposure and interpretation of chest X-ray.

RESULTS

From 278 children, standardized reading found 255 (91.7%) normal X-rays, 10 (3.6%) consistent with TB, and 13 (4.7%) other alterations. Global agreement was 91.3% (Kappa = 0.51). Inter-observer agreement between readers 1-2 was 90.0% (Kappa = 0.59) and 1-3 93.2% (Kappa = 0.59). Intra-observer agreement for reader 1 was 95.5% (Kappa = 0.86), 2 84.0% (Kappa = 0.51), and 3 94.7% (Kappa = 0.68). Greater inter-observer disagreement was between readers 1-2 for soft tissue density suggestive of adenopathy (4.6%), airspace opacification (1.17%) and pleural effusion (0.58%); between readers 1-3 for soft tissue density suggestive of adenopathy (4.2%), opacification of airspace (2.5%) and cavities (0.8%).

CONCLUSIONS

Chest radiographs are an affordable tool that contributes to the diagnosis of TB, so having a standardized reading protocol showed good agreement and improves the reproducibility of radiograph interpretation.

Diagnostic Advances in Childhood Tuberculosis—Improving Specimen Collection and Yield of Microbiological Diagnosis for Intrathoracic Tuberculosis

There is no microbiological gold standard for childhood tuberculosis (TB) diagnosis. The paucibacillary nature of the disease, challenges in sample collection in young children, and the limitations of currently available microbiological tests restrict microbiological confirmation of intrathoracic TB to the minority of children. Recent WHO guidelines recommend the use of novel rapid molecular assays as initial diagnostic tests for TB and endorse alternative sample collection methods for children. However, the uptake of these tools in high-endemic settings remains low. In this review, we appraise historic and new microbiological tests and sample collection techniques that can be used for the diagnosis of intrathoracic TB in children. We explore challenges and possible ways to improve diagnostic yield despite limitations, and identify research gaps to address in order to improve the microbiological diagnosis of intrathoracic TB in children.

Acute Intrathoracic Tuberculosis in Children and Adolescents with Community-Acquired Pneumonia in an Area with an Intermediate Disease Burden

Tuberculosis (TB) in the pediatric population is a major challenge. Our objective was to describe the clinical and microbiological characteristics, radiological patterns, and treatment outcomes of children and adolescents (from 1 month to 17 years) with community-acquired pneumonia (CAP) caused by TB. We performed a prospective cohort study of a pediatric population between 1 month and 17 years of age and hospitalized in Medellín, Colombia, with the diagnosis of radiologically confirmed CAP that had ≤ 15 days of symptoms. The mycobacterial culture of induced sputum was used for the bacteriological confirmation; the history of TB contact, a tuberculin skin test, and clinical improvement with treatment were used to identify microbiologically negative TB cases. Among 499 children with CAP, TB was diagnosed in 12 (2.4%), of which 10 had less than 8 days of a cough, 10 had alveolar opacities, 9 were younger than 5 years old, and 2 had close contact with a TB patient. Among the TB cases, 50% (6) had microbiological confirmation, 8 had viral and/or bacterial confirmation, one patient had multidrug-resistant TB, and 10/12 had non-severe pneumonia. In countries with an intermediate TB burden, Mycobacterium tuberculosis should be included in the etiological differential diagnosis (as a cause or coinfection) of both pneumonia and severe CAP in the pediatric population.

Global estimates of paediatric tuberculosis incidence in 2013-19: a mathematical modelling analysis

BACKGROUND

Many children who develop tuberculosis are thought to be missed by diagnostic and reporting systems. We aimed to estimate paediatric tuberculosis incidence and underreporting between 2013 and 2019 in countries representing more than 99% of the global tuberculosis burden.

METHODS

We developed a mathematical model of paediatric tuberculosis natural history, accounting for key mechanisms and risk factors for infectious exposure (HIV, malnutrition, and BCG non-vaccination), the probability of infection given exposure, and progression to disease among infected individuals. We extracted paediatric population estimates from UN Population Division data, and we used WHO estimates for adult tuberculosis incidence rates. We parameterised this model for 185 countries and calibrated it using data from countries with stronger case detection and reporting systems. Using this model, we estimated trends in paediatric incidence, and the proportion of these cases that are diagnosed and reported (case detection ratio [CDR]) for each country, age group, and year.

FINDINGS

For 2019, we estimated 997 500 (95% credible interval [CrI] 868 700-1 163 100) incident tuberculosis cases among children, with 481 000 cases (398 400-587 400) among those aged 0-4 years and 516 500 cases (442 900-608 000) among those aged 5-14 years. The paediatric CDR was estimated to be lower in children aged 0-4 years (41%, 95% CrI 34-50) than in those aged 5-14 years (63%, 53-75) and varied widely between countries. Estimated CDRs increased substantially over the study period, from 18% (15-20) in 2013 to 53% (45-60) in 2019, with improvements concentrated in the Eastern Mediterranean, South-East Asia, and Western Pacific regions. Over the study period, global incidence was estimated to have declined slowly at an average annual rate of 1·52% (1·42-1·66).

INTERPRETATION

Paediatric tuberculosis causes substantial morbidity and mortality, and these data indicate that cases (and, thus, probably associated mortality) are currently substantially underreported. These findings reinforce the need to ensure prompt diagnosis and care for children developing tuberculosis, strengthen reporting systems, and invest in research to develop more accurate and easy-to-use diagnostics for paediatric tuberculosis in high-burden settings.

FUNDING

National Institutes of Health.

Immunopathogenesis in HIV-associated pediatric tuberculosis

Tuberculosis (TB) is an increasing global emergency in human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) patients, in which host immunity is dysregulated and compromised. However, the pathogenesis and efficacy of therapeutic strategies in HIV-associated TB in developing infants are essentially lacking. Bacillus Calmette-Guerin vaccine, an attenuated live strain of Mycobacterium bovis, is not adequately effective, which confers partial protection against Mycobacterium tuberculosis (Mtb) in infants when administered at birth. However, pediatric HIV infection is most devastating in the disease progression of TB. It remains challenging whether early antiretroviral therapy (ART) could maintain immune development and function, and restore Mtb-specific immune function in HIV-associated TB in children. A better understanding of the immunopathogenesis in HIV-associated pediatric Mtb infection is essential to provide more effective interventions, reducing the risk of morbidity and mortality in HIV-associated Mtb infection in infants. IMPACT: Children living with HIV are more likely prone to opportunistic infection, predisposing high risk of TB diseases. HIV and Mtb coinfection in infants may synergistically accelerate disease progression. Early ART may probably induce immune reconstitution inflammatory syndrome and TB pathology in HIV/Mtb coinfected infants.

Abnormal Tryptophan Metabolism in HIV and Mycobacterium tuberculosis Infection

Host metabolism has recently gained more attention for its roles in physiological functions and pathologic conditions. Of these, metabolic tryptophan disorders generate a pattern of abnormal metabolites that are implicated in various diseases. Here, we briefly highlight the recent advances regarding abnormal tryptophan metabolism in HIV and Mycobacterium tuberculosis infection and discuss its potential impact on immune regulation, disease progression, and neurological disorders. Finally, we also discuss the potential for metabolic tryptophan interventions toward these infectious diseases.

Urine NMR-based TB metabolic fingerprinting for the diagnosis of TB in children

Tuberculosis (TB) is a major cause of morbidity and mortality in children, and early diagnosis and treatment are crucial to reduce long-term morbidity and mortality. In this study, we explore whether urine nuclear magnetic resonance (NMR)-based metabolomics could be used to identify differences in the metabolic response of children with different diagnostic certainty of TB. We included 62 children with signs and symptoms of TB and 55 apparently healthy children. Six of the children with presumptive TB had bacteriologically confirmed TB, 52 children with unconfirmed TB, and 4 children with unlikely TB. Urine metabolic fingerprints were identified using high- and low-field proton NMR platforms and assessed with pattern recognition techniques such as principal components analysis and partial least squares discriminant analysis. We observed differences in the metabolic fingerprint of children with bacteriologically confirmed and unconfirmed TB compared to children with unlikely TB (p = 0.041 and p = 0.013, respectively). Moreover, children with unconfirmed TB with X-rays compatible with TB showed differences in the metabolic fingerprint compared to children with non-pathological X-rays (p = 0.009). Differences in the metabolic fingerprint in children with different diagnostic certainty of TB could contribute to a more accurate characterisation of TB in the paediatric population. The use of metabolomics could be useful to improve the prediction of TB progression and diagnosis in children.

Diagnostic Performance of the Fujifilm SILVAMP TB-LAM in Children with Presumptive Tuberculosis

Current diagnostics for tuberculosis (TB) only manage to confirm a small proportion of children with TB and require respiratory samples, which are difficult to obtain. There is a need for non-invasive biomarker-based tests as an alternative to sputum testing. Fujifilm SILVAMP TB lipoarabinomannan (FujiLAM), a lateral-flow test to detect lipoarabinomannan in urine, is a novel non-sputum-based point-of-care diagnostic reported to have increased sensitivity for the diagnosis of TB among human immunodeficiency virus (HIV)-infected adults. We evaluate the performance of FujiLAM in children with presumptive TB. Fifty-nine children attending a paediatric hospital in Haiti with compatible signs and symptoms of TB were examined using Xpert MTB/RIF, smear microscopy and X-rays, and classified according to the certainty of diagnosis into bacteriologically confirmed TB (n = 5), unconfirmed TB (bacteriologically negative, n = 50) and unlikely TB (n = 4). Healthy children (n = 20) were enrolled as controls. FujiLAM sensitivity and specificity were 60% and 95% among children with confirmed TB. FujiLAM's high specificity and its characteristics as a point-of-care indicate the test has a good potential for the diagnosis of TB in children.

Tuberculosis in Children Hospitalized in a Low-burden Country: Description and Risk Factors of Severe Disease

BACKGROUND

In high-income countries, few pediatric studies have described the clinical expression of tuberculosis (TB) according to age, and their results are discordant. Patients <2 years of age are usually considered to be at higher risk for severe disease than older children. Our aim was to better describe pediatric TB disease severity in a low-incidence country.

METHODS

All children (<18 years of age) admitted with TB disease to the Robert Debré University Hospital, Paris, between 1992 and 2015 were included. Patients were classified by the severity of TB disease based on the original classification of Wiseman et al. Risk factors associated with severity were analyzed.

RESULTS

We included 304 patients with a median age of 9.9 years (interquartile range 3.3-13.3) and a male to female ratio of 1.04. Overall, 280/304 (92%) were classified: 168/304 (55%) were classified as showing severe TB and 112/304 (37%) as showing non-severe TB. Central nervous system disease was more frequent among patients <2 years of age than patients 2-17 years of age (5/54; 9% vs. 5/229; 2% P = 0.024). An age of ≥10 years (P = 0.001) and being born abroad (P = 0.011) were both associated with disease severity in univariate analysis. In multivariate analysis, diagnosis through symptom-based screening was independently associated with severity (odds ratio 7.1, 95% confidence interval: 3.9-12.9, P < 0.0001).

CONCLUSIONS

This description of the clinical spectrum of pediatric TB in a low-burden setting demonstrates that adolescents are the group most at risk of experiencing severe TB.

Tuberculosis in Pediatric Solid Organ and Hematopoietic Stem Cell Recipients

Children undergoing solid organ and hematopoietic stem cell transplantation are at high risk of morbidity and mortality from tuberculosis (TB) disease in the post-transplant period. Treatment of TB infection and disease in the post-transplant setting is complicated by immunosuppression and drug interactions. There are limited data that address the unique challenges for the management of TB in the pediatric transplant population. This review presents the current understanding of the epidemiology, clinical presentation, diagnosis, management, and prevention for pediatric transplant recipients with TB infection and disease. Further studies are needed to improve diagnosis of TB and optimize treatment outcomes for these patients.

Post-Tuberculosis Lung Disease: Clinical Review of an Under-Recognised Global Challenge

An estimated 58 million people have survived tuberculosis since 2000, yet many of them will suffer from post-tuberculosis lung disease (PTLD). PTLD results from a complex interplay between organism, host, and environmental factors and affects long-term respiratory health. PTLD is an overlapping spectrum of disorders that affects large and small airways (bronchiectasis and obstructive lung disease), lung parenchyma, pulmonary vasculature, and pleura and may be complicated by co-infection and haemoptysis. People affected by PTLD have shortened life expectancy and increased risk of recurrent tuberculosis, but predictors of long-term outcomes are not known. No data are available on PTLD in children and on impact throughout the life course. Risk-factors for PTLD include multiple episodes of tuberculosis, drug-resistant tuberculosis, delays in diagnosis, and possibly smoking. Due to a lack of controlled trials in this population, no evidence-based recommendations for the investigation and management of PTLD are currently available. Empirical expert opinion advocates pulmonary rehabilitation, smoking cessation, and vaccinations (pneumococcal and influenza). Exacerbations in PTLD remain both poorly understood and under-recognised. Among people with PTLD, the probability of tuberculosis recurrence must be balanced against other causes of symptom worsening. Unnecessary courses of repeated empiric anti-tuberculosis chemotherapy should be avoided. PTLD is an important contributor to the global burden of chronic lung disease. Advocacy is needed to increase recognition for PTLD and its associated economic, social, and psychological consequences and to better understand how PTLD sequelae could be mitigated. Research is urgently needed to inform policy to guide clinical decision-making and preventative strategies for PTLD.

Host-Based Biomarkers in Saliva for the Diagnosis of Pulmonary Tuberculosis in Children: A Mini-Review

The diagnosis of pulmonary tuberculosis (TB) in children remains a significant challenge due to its paucibacillary nature, non-specificity of symptoms and suboptimal sensitivity of available diagnostic methods. In young children particularly, it is difficult to obtain high-quality sputum specimens for testing, with this group the least likely to be diagnosed, while most at risk of severe disease. The World Health Organization (WHO) has prioritized research into rapid biomarker-based tests for TB using easily obtainable non-sputum samples, such as saliva. However, the role of biomarkers in saliva for diagnosing TB in children has not been fully explored. In this mini-review, we discuss the value of saliva as a diagnostic specimen in children given its ready availability and non-invasive nature of collection, and review the literature on the use of host-based biomarkers in saliva for diagnosing active pulmonary TB in adults and children. Based on available data from adult studies, we highlight that combinations of cytokines and other proteins show promise in reaching WHO-endorsed target product profiles for new TB triage tests. Given the lack of pediatric research on host biomarkers in saliva and the differing immune response to TB infection between children and adults, we recommend that pediatric studies are now performed to discover and validate salivary host biosignatures for diagnosing pulmonary TB in children. Future directions for pediatric saliva studies are discussed, with suggestions for technologies that can be applied for salivary biomarker discovery and point-of-care test development.

Characteristics of paediatric patients with tuberculosis and associated determinants of treatment success in Malaysia using the MyTB version 2.1 database over five years

Background

Tuberculosis (TB) among children remains a significant public health problem in many parts of the world. The objective of this study was to describe the characteristics of TB patients and to determine the predictors of treatment success among children in Malaysia.

Methods

Secondary data from MyTB version 2.1, a national database, were analysed using R version 3.6.1. Descriptive analysis and multivariable logistic regression were conducted to identify treatment success and its determinants.

Results

In total, 3630 cases of TB cases were registered among children in Malaysia between 2013 and 2017. The overall treatment success rate was 87.1% in 2013 and plateaued between 90.1 and 91.4% from 2014 to 2017. TB treatment success was positively associated with being a Malaysian citizen (aOR = 3.43; 95% CI = 2.47, 4.75), being a child with BCG scars (aOR = 1.93; 95% CI = 1.39, 2.68), and being in the older age group (aOR = 1.06; 95% CI = 1.03, 1.09). Having HIV co-infection (aOR = 0.31; 95% CI = 0.16, 0.63), undergoing treatment in public hospitals (aOR = 0.38; 95% CI =0.25, 0.58), having chest X-ray findings of advanced lesion (aOR = 0.48; 95% CI = 0.33, 0.69), having EPTB (aOR = 0.58; 95% CI = 0.41, 0.82) and having sputum-positive PTB (aOR = 0.58; 95% CI = 0.43, 0.79) were negatively associated with TB treatment success among children.

Conclusions

The overall success rate of treatment among children with TB in Malaysia has achieved the target of 90% since 2014 and remained plateaued until 2017. The socio-demographic characteristics of children, place of treatment, and TB disease profile were associated with the likelihood of TB treatment success among children. The treatment success rate can be increased by strengthening contact tracing activities and promoting early identification targeting the youngest children and non-Malaysian children.

Caracterización de los pacientes menores de 15 años con tuberculosis en el Hospital Universitario San Vicente Fundación, 2011-2018

La Tuberculosis (TB) es la enfermedad infecciosa que más daño ha causado a la especie humana a lo largo de toda la historia, tanto por el número de enfermos como de muertos. Se ha calculado que en los últimos 200 años ha sido la responsable de la muerte de más de 1.000 millones de personas (1). La TB sigue siendo una de las enfermedades infecciosas más importante en esta época, y es el fiel reflejo de las enormes diferencias económicas y sociales que siguen existiendo en la población mundial1,2. Objetivo: describir las características demográficas y clínicas de los pacientes menores de 15 años con TB en el período 2011 – 2018 en un Hospital de cuarto nivel de la ciudad de Medellín – Colombia. Metodología: estudio observacional descriptivo de corte transversal. Incluyó pacientes menores de 15 años que asistieron al Hospital Universitario San Vicente Fundación (HUSVF) a quienes se les diagnosticó TB pulmonar y/o extrapulmonar, en el período comprendido entre enero de 2011 a diciembre de 2018. Resultados: 184 historias de pacientes con TB cumplieron los criterios de inclusión. Setenta y un pacientes (38.6 %) correspondían a TB pulmonar, 59 (32 %) a otras TB intratorácicas y 54 (29.3 %) a TB extrapulmonar. Las formas de TB más frecuentes fueron: ganglionar, del sistema nervioso central (SNC) y diseminada. De los niños menores de 5 años, el 50 % presentaron algún grado de desnutrición. La confirmación microbiológica por cultivo o baciloscopia (BK) estuvo presente en 91 pacientes (49.4 %) y por Reacción en Cadena de la Polimerasa (PCR) en 72 (39.1 %). Conclusiones: la TB infantil requiere un alto índice de sospecha. La suma de criterios es muy importante para su diagnóstico dada la fisiopatología de la enfermedad, sin embargo la búsqueda exhaustiva de la micobacteria es una estrategia útil para un tratamiento efectivo.

Soluble urokinase-type plasminogen activator receptor as a biomarker of treatment response in childhood tuberculosis

Background

Childhood tuberculosis (TB) is a major health problem worldwide, especially in developing countries. In 2015, there are estimated 950,000 cases of childhood TB. Since most TB in children is paucibacillary, this gives rise not only to problem in diagnosing but also in monitoring the response to anti-TB treatment as well. Soluble urokinase-type plasminogen activator receptor (suPAR), a glycosylphosphatidylinositol-linked membrane protein of various cells of immune system, is one of the potential biomarkers to be used in the management of TB. The objective of this study is to study the decrease of serum suPAR level after anti-TB treatment in children with TB and its association with patient characteristics.

Methods

We conducted a prospective study on children suspected of having TB due to a history of contact with active TB case and symptoms such as coughing, fever, and enlarged lymph nodes. The diagnosis of TB is established by history, physical examination including anthropometric examination. Tuberculin skin test using PPD RT-23 and interferon-gamma releasing assay with Quantiferon TB-Gold Plus was performed. Chest X-rays were read by two independent radiologists. Microbiological examination was performed using microscopic examination and Xpert MTB/RIF. The level of suPAR before and after anti-TB treatment was examined with the Elisa method.

Results

There was no significant difference of serum suPAR levels before and after anti-TB treatment (mean 0.71 [standard deviation 0.585] ng/mL; P = 0.072). There was no association between ages (P = 0.112), nutritional status (P = 0.228), diagnosis of pulmonary or extrapulmonary TB (P = 0.956), and radiological feature (P = 0.810) with serum suPAR levels decrease.

Conclusion

There is no suPAR serum level decrease 2 months after treatment with anti-TB and there is no association with age, nutritional status, pulmonary or extrapulmonary TB diagnosis, and radiological feature.

Development and biological evaluation of a new nanotheranostic for tuberculosis

In this study, we developed, characterized, and tested in vivo polymeric nanoparticle of ethambutol labeled with 99mTc as nanoradiopharmaceutical for early diagnosis of tuberculosis by single-photon emission computed tomography, also as a therapeutic choice. Nanoparticles were developed by double emulsification. All characterization tests were performed, as scanning electron microscopy and dynamic light scattering. The labeling process with 99mTc was performed using the direct labeling process. In vitro and in vivo assays were performed with animals and cells. The results showed that a spherical ethambutol nanoparticle with a size range of 280-300 nm was obtained. The stability test showed that the nanoparticles were well labeled with 99mTc (> 99.1%) and keep labeled over 24 h. The biodistribution assay showed that almost 18% of the nanoparticles were uptake by the lung in infected mice (male C57Bl/6) with Mycobacterium bovis BCG (4 × 10⁵ CFU/cavity), corroborating its use as a nanodrug for tuberculosis imaging. The results for the cell assay corroborate its therapeutical effect. We developed and efficiently tested a new nanodrug that can be used for both imaging and therapy of tuberculosis, acting as a novel nanotheranostic.

Childhood tuberculosis in Vienna between 2010 and 2016

BACKGROUND

Tuberculosis (TB) has become a rare disease in developed countries. Austria is a low incidence country for TB with an incidence rate of 7.2/100,000 in 2016. The incidence of TB has shown a constant decline in Austria from 2008 (9.8/100,000) to 2015 (6.7/100,000) but recently stagnated in 2016 (7.2/100,000). In recent years migration to Austria from countries with high TB incidence rates has increased. Therefore, this study aimed to describe the recent epidemiology of childhood TB in Vienna.

METHODS

Data of pediatric patients with active TB infections, who were hospitalized for further investigations or isolation precautions between 2010 and 2016 at the Wilhelminenspital, Austria's reference center for childhood tuberculosis, were retrospectively analyzed. Demographic and clinical data (symptoms, microbiology, radiology, immunology) were collected, compared and evaluated.

RESULTS

A total of 127 patients with active tuberculosis were included in the study. The number of admissions varied between n = 7 in 2010 and n = 26 in 2016. There were two age peaks of infected children (0-5 years: n = 41 and 15-18 years: n = 45). In 35% of the cases one parent had active TB and was suspected to be the index case. In 36% the source of infection remained unknown. Compared to young children (<5 years), adolescents (15-18 years) showed proportionally more TB-related symptoms, such as cough (41% vs. 24%), fever (15% vs. 14%) and weight loss (22% vs. 0%). At the time of admission 51% of the young children and 33% of the adolescents were free of symptoms. Intrathoracic disease was found in 80.8%, extrathoracic disease in 19.2% and 11% of the cases were tuberculous lymphadenitis. Of the patients with intrathoracic TB 54% (n = 64) had a positive microbiological result (auramine staining, bacteriological culture, PCR). In young children hilar lymphadenopathy was the most frequent radiological finding (50%), whereas in adolescents lung infiltrates were most common (36%). The sensitivity of interferon-gamma release assays (IGRA) was 0.94 compared to 0.88 of the tuberculin skin test (TST). Both test methods showed moderate concordance (ϕ-coefficient = 0.48).

CONCLUSION

A high number of asymptomatic children and adolescents with active TB were observed, which underlines the importance of efficient screening measures. Thorough history taking in all patients with TB is essential to maximize the effect of contact tracing. Overall, infection rates remained consistently low during the observation period.

Tuberculous pneumonia-induced severe ARDS complicated with DIC in a female child: a case of successful treatment

Background

Tuberculous (TB) pneumonia can induce acute respiratory distress syndrome (ARDS). Although TB pneumonia is one of the causes of disease and death among children worldwide, the literature on TB pneumonia-induced ARDS is limited. We report herein on the successful treatment of a two-year-old female child with TB pneumonia-induced severe ARDS complicated with disseminated intravascular coagulation (DIC).

Case presentation

A two-year-old Vietnamese female child with sustained fever and cough for 20 days was transferred to our hospital. She had severe dyspnea and a chest X-ray showed bilateral infiltration without findings of heart failure. After tracheal intubation, her oxygenation index (OI) and PaO₂/FiO₂ (PF) ratio were 29 and 60 mmHg, respectively. Mycobacterium tuberculosis was detected by real-time polymerase chain reaction (rPCR) assay of tracheal lavage fluid. She was diagnosed as having severe ARDS that developed from TB pneumonia. Anti-tuberculous therapy and cardiopulmonary support were started. However, her respiratory condition deteriorated despite treatment with high-frequency oscillating ventilation (HFO), vasopressor support, and 1 g/kg of immunoglobulin. On the third day after admission, her International Society on Thrombosis and Hemostasis DIC score had increased to 5. Recombinant human soluble thrombomodulin (rTM) was administered to treat the DIC. After the administration of rTM was completed, OI gradually decreased, after which the mechanical ventilation mode was changed from HFO to synchronized intermittent mandatory ventilation. The DIC score also gradually decreased. Plasma levels of soluble receptor for advanced glycan end products (sRAGE) and high mobility group box 1 (HMGB-1), which are reported to be associated with ARDS severity, also decreased. In addition, inflammatory biomarkers, including interferon-gamma (IFN-γ) and interleukin-6 (IL-6), decreased after the administration of rTM. Although severe ARDS (P/F ratio ≦ 100 mmHg) continued for 19 days, the patient’s OI and P/F ratio improved gradually, and she was extubated on the 27th day after admission. The severe ARDS with DIC was successfully treated, and she was discharged from hospital on day 33 post-admission.

Conclusions

We successfully treated a female child suffering from TB pneumonia-induced severe ARDS complicated with DIC using multimodal interventions. (338/350).

A systematic approach to diagnosing intra-thoracic tuberculosis in children

Children suffer a huge and often underappreciated burden of disease in tuberculosis (TB) endemic countries. Major hurdles include limited awareness among health care workers, poor integration of TB into maternal and child health approaches, diagnostic difficulties and a lack of child-friendly treatment options. Accurate disease diagnosis is particularly difficult in young and vulnerable children who tend to develop paucibacillary disease and are unable to produce an expectorated sputum sample. In addition, access to chest radiography is problematic in resource-limited settings. Differentiating between TB exposure and M. tuberculosis infection, and especially between M. tuberculosis infection and TB disease is crucial to guide clinical management. TB represents a dynamic continuum from well-contained "latent" infection to incipient and ultimately severe disease. The clinical spectrum of disease in children is broad and can be confused with a myriad of common infections. We provide a pragmatic 4-step approach to diagnose intra-thoracic TB in children and demonstrate how classifying clinical, radiological and laboratory findings into recognised clinical syndromes may provide a more refined diagnostic approach, even in resource-limited settings.

Drug-Resistant tuberculosis - primary transmission and management

The DOTS strategy assisted global tuberculosis (TB) control, but was unable to prevent the emergence and spread of drug-resistant strains. Genomic evidence confirms the transmission of drug-resistant Mycobacterium tuberculosis strains in many different settings, indicative of epidemic spread. These findings emphasise the need for enhanced infection control measures in health care and congregate settings. Young children in TB endemic areas are particularly vulnerable. Although advances in TB drug and vaccine development are urgently needed, improved access to currently available preventive therapy and treatment for drug resistant TB could reduce the disease burden and adverse outcomes experienced by children. We review new insights into the transmission dynamics of drug resistant TB, the estimated disease burden in children and optimal management strategies to consider.

Acquired heart disease in low-income and middle-income countries

The burden of illness associated with acquired cardiac disease in children in low-income and middle-income countries (LMIC) is significant and may be equivalent to that of congenital heart disease. Rheumatic heart disease, endomyocardial fibrosis, cardiomyopathy (including HIV cardiomyopathy) and tuberculosis are the most important causes. All are associated with poverty with the neediest children having the least access to care. The associated mortality and morbidity is high. There is an urgent need to improve cardiac care in LMIC, particularly in sub-Saharan Africa and parts of Southeast Asia where the burden is highest.

Age-Stratified T Cell Responses in Children Infected with Mycobacterium tuberculosis

Tuberculosis (TB) in young children differs from adult TB in that the risk of rapid progression to active TB (aTB) is higher in children than in adults. The reasons for this increased risk are not fully understood. Early differentiation remains difficult between children at risk to develop aTB from those who will remain healthy and develop a latent TB infection (LTBI). Biomarkers to differentiate aTB from LTBI in children, especially in very young children, are urgently needed. To identify M. tuberculosis-specific functional T cell subsets related to clinical manifestations in children, we enrolled 87 children exposed to M. tuberculosis. After standard clinical assessment, the children were classified as aTB, LTBI, or uninfected. Their CD4⁺ T cell cytokine profiles (IFN-γ, TNF-α, IL-2, IL-17) were analyzed at the single-cell level by flow cytometry after stimulation with three mycobacterial antigens, purified protein derivative (PPD), early-secreted-antigenic target-6 (ESAT-6), or heparin-binding hemagglutinin (HBHA). This approach identified age-related discriminative markers between aTB and LTBI. Whereas among the 3- to 15-year-old children, an excellent discrimination between aTB and LTBI was provided by comparing the ratio between the proportions of ESAT-6-induced IFN-γ^single+ and ESAT-6-induced TNF-α^single+CD4⁺ T lymphocytes, this was not the case for children younger than 3 years. By contrast, in this group (<3years), the analysis of HBHA-induced IL-17^single+CD4⁺ T lymphocytes allowed us to identify children with LTBI by the high proportion of this cellular lymphocyte subset, whereas this was not the case for children with aTB. The analysis at the single-cell level of T cell immune responses induced by mycobacterial antigens are, thus, different in infected children younger or older than 3 years of age. HBHA-induced IL-17 production by CD4⁺ T lymphocytes was associated with protection only in children under 3 years who are at high risk for rapid progression to aTB. This suggests that the HBHA-induced IL-17 production by CD4⁺ T lymphocytes is a potential new correlate of protection against M. tuberculosis in humans, and that the distinction between children with LTBI and those with aTB is possible based on age-related diagnostic markers.

Role of Interferons in the Development of Diagnostics, Vaccines, and Therapy for Tuberculosis

Tuberculosis (TB) is an airborne infection caused by Mycobacterium tuberculosis (Mtb). About one-third of the world's population is latently infected with TB and 5–15% of them will develop active TB in their lifetime. It is estimated that each case of active TB may cause 10–20 new infections. Host immune response to Mtb is influenced by interferon- (IFN-) signaling pathways, particularly by type I and type II interferons (IFNs). The latter that consists of IFN-γ has been associated with the promotion of Th1 immune response which is associated with protection against TB. Although this aspect remains controversial at present due to the lack of established correlates of protection, currently, there are different prophylactic, diagnostic, and immunotherapeutic approaches in which IFNs play an important role. This review summarizes the main aspects related with the biology of IFNs, mainly associated with TB, as well as presents the main applications of these cytokines related to prophylaxis, diagnosis, and immunotherapy of TB.

Improving access to tuberculosis preventive therapy and treatment for children

Children suffer a huge burden of disease in tuberculosis (TB) endemic countries. This disease burden was largely invisible when TB control programmes focused exclusively on adults with sputum smear-positive disease. High-level advocacy and better data have improved visibility, but the establishment of functional paediatric TB programmes remains challenging. The key issues that limit children's access to TB preventive therapy and treatment in endemic areas are briefly discussed. Barriers to preventive therapy include (1) the perceived inability to rule out active disease, (2) fear of creating drug resistance, (3) non-implementation of existing guidelines in the absence of adequate monitoring, and (4) poor adherence with long preventive therapy courses. Barriers to TB treatment include (1) perceived diagnostic difficulties, (2) non-availability of chest radiography, (3) young children presenting to unprepared maternal and child health (MCH) services, and (4) the absence of child-friendly formulations. With drug-resistant disease there is currently no guidance on the use of preventive therapy and treatment is usually restricted to cases with bacteriologically confirmed disease, which excludes most young children from care, even if their likely source case has documented drug-resistant TB.